Since September 2018 and as of Feb 5, 53,459 have been reported, 676 of them lab-confirmed.

There are pockets of anti-vaccine sentiment throughout the Northwest, Lynch explained: "There's a group of people who say "you don't tell me what to do". The Oregonian reports that yesterday was the third consecutive day with no new cases reported, but they say it's too early to say the outbreak is over.

The United Nations said Tuesday that almost 22,000 measles cases were reported in the country in 2018.

Health Secretary Francisco Duque III appealed to the public to repose their trust and confidence in immunization programmes.

A way for vaccines to work effectively is "herd immunization" -- meaning if enough of a population is immune, those who aren't will be more protected. "This means that gaps at local level still offer an open door to the virus", says Dr Zsuzsanna Jakab, Director of the WHO's Regional Office for Europe in Copenhagen.

"Our country's immunisation programme is now in a quandary and our children's health is under threat because of the vaccine scare triggered by Acosta's grandstanding to be in Duterte's good graces", said Senator Leila De Lima, who has been jailed on drug charges following her probe into killings in Duterte's war on drugs. Some data suggests that in kids who haven't been exposed to dengue before, the vaccine can act as a priming event and subsequently lead to more severe infections.

Last April, a World Health Organization expert committee advised against use of the vaccine without tests to confirm prior dengue infection.